Framework for personalized prediction of treatment response in relapsing remitting multiple sclerosis.

BACKGROUND: Personalized healthcare promises to successfully advance the treatment of heterogeneous neurological disorders such as relapsing remitting multiple sclerosis by addressing the caveats of traditional healthcare. This study presents a framework for personalized prediction of treatment response based on real-world data from the NeuroTransData network. METHODS: A framework for personalized prediction of response to various treatments currently available for relapsing remitting multiple sclerosis patients was proposed. Two indicators of therapy effectiveness were used: number of relapses, and confirmed disability progression. The following steps were performed: (1) Data preprocessing and selection of predictors according to quality and inclusion criteria; (2) Implementation of hierarchical Bayesian generalized linear models for estimating treatment response; (3) Validation of the resulting predictive models based on several performance measures and routines, together with additional analyses that focus on evaluating the usability in clinical practice, such as comparing predicted treatment response with the empirically observed course of multiple sclerosis for different adherence profiles. RESULTS: The results revealed that the predictive models provide robust and accurate predictions and generalize to new patients and clinical sites. Three different out-of-sample validation schemes (10-fold cross-validation, leave-one-site-out cross-validation, and excluding a test set) were employed to assess generalizability based on three different statistical performance measures (mean squared error, Harrell's concordance statistic, and negative log-likelihood). Sensitivity to different choices of the priors, to the characteristics of the underlying patient population, and to the sample size, was assessed. Finally, it was shown that model predictions are clinically meaningful. CONCLUSIONS: Applying personalized predictive models in relapsing remitting multiple sclerosis patients is still new territory that is rapidly evolving and has many challenges. The proposed framework addresses the following challenges: robustness and accuracy of the predictions, generalizability to new patients and clinical sites and comparability of the predicted effectiveness of different therapies. The methodological and clinical soundness of the results builds the basis for a future support of patients and doctors when the current treatment is not generating the desired effect and they are considering a therapy switch. (A) The framework is developed using quality-proven real-world data of patients with relapsing remitting multiple sclerosis. Patients have heterogeneous individual characteristics and diverse disease profiles, indicated for example by variations in frequency of relapses and degree of disability. Longitudinal characteristics regarding disease history (e.g. number of previous relapses in the last 12 months) are extracted at the time of an intended therapy switch, i.e. at time point "Today" (left). All clinical parameters are captured in a standardized way (right). (B) The model predicts the course of the disease based on the observed data (panel A), and is able to account for the impact of various available therapies on chosen clinical endpoints. The resulting ranking of therapies has a dependency on patient characteristics, illustrated here by a different highest ranked therapy depending on the number of relapse in the previous 12 months. (C) The model is evaluated for various generalization properties. Compared to performance on the training set (gray) it is able to predict for new patients not part of the training set (red).Top: Prediction for new patients. Middle: Prediction for new clinical sites. Bottom: Prediction for different time windows. (D) In order to assess the clinical impact of the model, disease activity is compared between patients treated with the highest ranked therapy and those treated with any of the other therapies. Patients adhering to the highest ranked therapy are associated with a better disease outcome when compared to those who did not.

QIL1-dependent assembly of MICOS complex-lethal mutation in C19ORF70 resulting in liver disease and severe neurological retardation.

Seven subunits of the mitochondrial contact site and cristae junction (CJ) organizing system (MICOS) in humans have been recently described in function and structure. QIL1 (also named MIC13) is a small complex that is crucial for the maintenance and assembling of MICOS. A novel mutation of an essential splice site in the C19orf70 gene encoding QIL1 induces severe mitochondrial encephalopathy, hepatopathy and lactate acidosis consistent with psychomotor retardation. In addition, bilateral kidney stones were observed. Disassembly of MICOS complex subunits displays lack of MIC10-MIC26-MIC27-QIL1 subcomplex, resulting in aberrant cristae structure and a loss of cristae junctions and contact sites. In liver and muscle tissue, the activity of the respiratory chain complexes (OXPHOS) was severely impaired. Defects in MICOS complex do not only affect mitochondrial architecture, but also mitochondrial fusion, metabolic signalling, lipid trafficking and cellular electric homeostasis.

Reproducibility of right-to-left shunt quantification using transthoracic contrast echocardiography in hereditary haemorrhagic telangiectasia.

AIM: Transthoracic contrast echocardiography (TTCE) is recommended for screening of pulmonary arteriovenous malformations (PAVMs) in hereditary haemorrhagic telangiectasia. Shunt quantification is used to find treatable PAVMs. So far, there has been no study investigating the reproducibility of this diagnostic test. Therefore, this study aimed to describe inter-observer and inter-injection variability of TTCE. METHODS: We conducted a prospective single centre study. We included all consecutive persons screened for presence of PAVMs in association with hereditary haemorrhagic telangiectasia in 2015. The videos of two contrast injections per patient were divided and reviewed by two cardiologists blinded for patient data. Pulmonary right-to-left shunts were graded using a three-grade scale. Inter-observer and inter-injection agreement was calculated with κ statistics for the presence and grade of pulmonary right-to-left shunts. RESULTS: We included 107 persons (accounting for 214 injections) (49.5% male, mean age 45.0 ± 16.6 years). A pulmonary right-to-left shunt was present in 136 (63.6%) and 131 (61.2%) injections for observer 1 and 2, respectively. Inter-injection agreement for the presence of pulmonary right-to-left shunts was 0.96 (95% confidence interval (CI) 0.9-1.0) and 0.98 (95% CI 0.94-1.00) for observer 1 and 2, respectively. Inter-injection agreement for pulmonary right-to-left shunt grade was 0.96 (95% CI 0.93-0.99) and 0.95 (95% CI 0.92-0.98) respectively. There was disagreement in right-to-left shunt grade between the contrast injections in 11 patients (10.3%). Inter-observer variability for presence and grade of the pulmonary right-to-left shunt was 0.95 (95% CI 0.91-0.99) and 0.97 (95% CI 0.95-0.99) respectively. CONCLUSION: TTCE has an excellent inter-injection and inter-observer agreement for both the presence and grade of pulmonary right-to-left shunts.

Follow-up of Thalidomide treatment in patients with Hereditary Haemorrhagic Telangiectasia.

BACKGROUND: Patients with a hereditary vascular disorder called Rendu-Osler-Weber syndrome (Hereditary Haemorrhagic Telangiectasia, HHT) haemorrhage easily due to weak-walled vessels. Haemorrhage in lungs or brain can be fatal but patients suffer most from chronic and prolonged nosebleeds (epistaxis), the frequency and intensity of which increases with age. Several years ago, it was discovered serendipitously that the drug Thalidomide had beneficial effects on the disease symptoms in several of a small group of HHT patients: epistaxis and the incidence of anaemia were reduced and patients required fewer blood transfusions. In addition, they reported a better quality of life. However, Thalidomide has significant negative side effects, including neuropathy and fatigue. METHODS: We followed up all HHT patients in the Netherlands who had been taking Thalidomide at the time the original study was completed to find out (i) how many had continued taking Thalidomide and for how long (ii) the nature and severity of any side-effects and (iii) whether side-effects had influenced their decision to continue taking Thalidomide. RESULTS: Only a minority of patients had continued taking the drug despite its beneficial effects on their symptoms and that the side effects were the primary reason to stop. CONCLUSION: Despite symptom reduction, alternative treatments are still necessary for epistaxis in HHT patients and a large-scale clinical trial is not justified although incidental use in the most severely affected patients can be considered.

International guidelines for the diagnosis and management of hereditary haemorrhagic telangiectasia.

BACKGROUND: HHT is an autosomal dominant disease with an estimated prevalence of at least 1/5000 which can frequently be complicated by the presence of clinically significant arteriovenous malformations in the brain, lung, gastrointestinal tract and liver. HHT is under-diagnosed and families may be unaware of the available screening and treatment, leading to unnecessary stroke and life-threatening hemorrhage in children and adults. OBJECTIVE: The goal of this international HHT guidelines process was to develop evidence-informed consensus guidelines regarding the diagnosis of HHT and the prevention of HHT-related complications and treatment of symptomatic disease. METHODS: The overall guidelines process was developed using the AGREE framework, using a systematic search strategy and literature retrieval with incorporation of expert evidence in a structured consensus process where published literature was lacking. The Guidelines Working Group included experts (clinical and genetic) from eleven countries, in all aspects of HHT, guidelines methodologists, health care workers, health care administrators, HHT clinic staff, medical trainees, patient advocacy representatives and patients with HHT. The Working Group determined clinically relevant questions during the pre-conference process. The literature search was conducted using the OVID MEDLINE database, from 1966 to October 2006. The Working Group subsequently convened at the Guidelines Conference to partake in a structured consensus process using the evidence tables generated from the systematic searches. RESULTS: The outcome of the conference was the generation of 33 recommendations for the diagnosis and management of HHT, with at least 80% agreement amongst the expert panel for 30 of the 33 recommendations.

[Burnout among elderly care staff. A review of its prevalence]. / Burn-out bei Beschäftigten in der stationären Altenpflege und in der Geriatrie. Ein Review zur Prävalenz.

Provision of inpatient elderly care is characterized by factors that favor the onset of burnout, with psychosomatic complaints, a drop in performance, periods of absence due to sickness, and early retirement from the sector regularly being observed in this respect. This study summarizes the research of the past 11 years, regarding the prevalence of burnout among inpatient elderly care employees. A total of 24 studies were identified during a systematic database search conducted in May 2011. As the studies conceptualize burnout differently and are based on different survey tools, it is not possible to draw a clear conclusion regarding its prevalence. There is empirical evidence of a correlation between burnout and the care staff/patient ratio, workloads, the freedom to make decisions, job satisfaction, and neuroticism. There is no confirmation of a correlation between burnout and marital status, income, or shift work. There are contradictory findings regarding the correlation between burnout and sociodemographic aspects (e.g., age and gender) as well as burnout and the type of care institution, working hours, and violence perpetrated by patients.

Atypical myopathy: a review and description of the outbreak in the Netherlands during autumn 2009 and spring 2010.

This article reviews the literature on equine atypical myopathy (AM), an acute, severe rhabdomyolysis that occurs in horses at pasture. The prevalence, mortality, clinical signs, pathology, potential aetiology, typical aspects, diagnosis, treatment, and prognosis are described. Horse management, characteristic weather conditions, and possible preventive measures are also discussed. In addition, the characteristics of 54 highly probable or confirmed cases of equine AM occurring between autumn 2009 (27 cases) and spring 2010 (27 cases) in the Netherlands are described. Of the 54 affected horses, nineteen were mares, eleven geldings, and eight stallions; the sex of the other sixteen horses was not recorded. The mortality rate (74.5%) was in the same range as that reported in earlier studies. Many cases were reported at about the same time. Thirty-five horses had been pastured near maple trees, and in fifteen cases the maple trees were known to be infected with the fungus Rhytisma acerinum.

Decreased oxidative phosphorylation and PGAM deficiency in horses suffering from atypical myopathy associated with acquired MADD.

Earlier research on ten horses suffering from the frequently fatal disorder atypical myopathy showed that MADD (multiple acyl-CoA dehydrogenase deficiency) is the biochemical derangement behind atypical myopathy. From five horses that died as a result of this disease and seven healthy control horses, urine and plasma were collected ante mortem and muscle biopsies were obtained immediately post-mortem (2 patients and 7 control horses), to analyse creatine, purine and carbohydrate metabolism as well as oxidative phosphorylation. In patients, the mean creatine concentration in urine was increased 17-fold and the concentration of uric acid approximately 4-fold, compared to controls. The highest degree of depletion of glycogen was observed in the patient with the most severe myopathy clinically. In this patient, glycolysis was more active than in the other patients and controls, which may explain this depletion. One patient demonstrated very low phosphoglycerate mutase (PGAM) activity, less than 10% of reference values. Most respiratory chain complex activity in patients was 20-30% lower than in control horses, complex II activity was 42% lower than normal, and one patient had severely decrease ATP-synthase activity, more than 60% lower than in control horses. General markers for myopathic damage are creatine kinase (CK) and lactic acid in plasma, and creatine and uric acid in urine. To obtain more information about the cause of the myopathy analysis of carbohydrate, lipid and protein metabolism as well as oxidative phosphorylation is advised. This study expands the diagnostic possibilities of equine myopathies.

Equine acquired multiple acyl-CoA dehydrogenase deficiency (MADD) in 14 horses associated with ingestion of Maple leaves (Acer pseudoplatanus) covered with European tar spot (Rhytisma acerinum).

This case-series describes fourteen horses suspected of equine acquired multiple acyl-CoA dehydrogenase deficiency (MADD) also known as atypical myopathy of which seven cases were confirmed biochemically with all horses having had access to leaves of the Maple tree (Acer pseudoplatanus) covered with European tar spot (Rhytisma acerinum). Assessment of organic acids, glycine conjugates, and acylcarnitines in urine was regarded as gold standard in the biochemical diagnosis of equine acquired multiple acyl-CoA dehydrogenase deficiency.

Screening for pulmonary arteriovenous malformations using transthoracic contrast echocardiography: a prospective study.

Pulmonary arteriovenous malformations (PAVMs) are associated with severe neurological complications in patients with hereditary haemorrhagic telangiectasia (HHT). The objective of the present study was to prospectively establish the diagnostic value of transthoracic contrast echocardiography (TTCE) as a screening technique for PAVM using chest high-resolution computed tomography (HRCT) as the gold standard for PAVMs. All consecutive adult patients referred for HHT screening underwent a chest HRCT (n = 299), TTCE (n = 281), arterial blood gas analysis (n = 291), shunt fraction measurement (n = 111) and chest radiography (n = 296). TTCE was positive in 87 (58.8%), 12 (16.7%) and four (6.7%) patients, and chest HRCT was positive in 54 (36.5%), three (4.2%) and zero (0%) patients with a definite, possible and negative clinical diagnosis of HHT, respectively. Two patients with a negative TTCE were diagnosed with PAVMs after computed tomography; in both cases the PAVMs were too small to be treated by embolotherapy. The sensitivity of TTCE was 97% (95% confidence interval (CI) 93.6-98.3) and negative predictive value 99% (95% CI 96.9-99.8). The other diagnostic tests showed a considerable lower diagnostic value. The present prospective study shows that transthoracic contrast echocardiography has an excellent diagnostic value and can be used as an initial screening procedure for pulmonary arteriovenous malformations. The high false-positive rate of transthoracic contrast echocardiography possibly represents microscopic pulmonary arteriovenous malformations.

Pulmonary arteriovenous malformations associated with migraine with aura.

Migraine with aura (MA) is associated with cardiac right-to-left shunt. We prospectively studied the association between pulmonary arteriovenous malformations (PAVMs) and MA in hereditary haemorrhagic telangiectasia (HHT). All 220 consecutive HHT patients who underwent high-resolution chest computed tomography for PAVM screening were included prospectively. Prior to screening, a structured validated headache questionnaire was completed by 196 patients (57% female; mean+/-sd age 44.6+/-15.2 yrs). Two neurologists diagnosed migraine according to the International Headache Society Criteria. A PAVM was present in 70 (36%) patients. The prevalence of MA was 24% in the presence of a PAVM compared with 6% in the absence of a PAVM (OR 4.6, 95% CI 1.84-11.2; p = 0.001), and MA was an independent predictor for the presence of PAVM using multivariate analysis (OR 3.6, 95% CI 1.21-10.5; p = 0.02). A PAVM was present in 68% of the patients with MA compared with 32% in the non-migraine controls (OR 4.6, 95% CI 1.84-11.2; p = 0.001), and a PAVM was an independent predictor for MA using multivariate analysis (OR 3.0, 95% CI 1.00-9.20; p = 0.05). In conclusion, PAVMs are associated with MA in HHT patients.

The effect of N-acetylcysteine on epistaxis and quality of life in patients with HHT: a pilot study.

BACKGROUND: Free O2- radicals may cause precapillary sphincter abnormalities, resulting in epistaxis in hemizygous knockout mice for Endoglin. The objective of this study was to test if antioxidants, like N-acetylcysteine (NAC), are have a role in the treatment of epistaxis in hereditary hemorrhagic telangiectasia (HHT). METHODS: Forty-three patients participated in this study taking NAC 600 mg t.i.d for 12 weeks. Patients registered frequency, severity and duration of epistaxis and private and work-related quality of life (QOL), using a diary for two 6 weeks periods. The first period was prior to starting treatment and the second started after 6 weeks using NAC. RESULTS: There was a decrease infrequency (p < 0.01) and severity (p < 0.01) of epistaxis during the day. The improvement was most remarkable in male patients and patients with an ENDOGLIN mutation. In women and patients with an ALK-1 mutation, only a trend for improvement was found. Nocturnal epistaxis did not improve. The effect of epistaxis on the ability to work (p = 0.02) was reduced. CONCLUSION: This pilot study was conducted to investigate whether animal experiments can be translated to humans with HHT regarding epistaxis. The positive results with NAC are promising and justify a randomised clinical trial.

Acquired multiple Acyl-CoA dehydrogenase deficiency in 10 horses with atypical myopathy.

The aim of the current study was to assess lipid metabolism in horses with atypical myopathy. Urine samples from 10 cases were subjected to analysis of organic acids, glycine conjugates, and acylcarnitines revealing increased mean excretion of lactic acid, ethylmalonic acid, 2-methylsuccinic acid, butyrylglycine, (iso)valerylglycine, hexanoylglycine, free carnitine, C2-, C3-, C4-, C5-, C6-, C8-, C8:1-, C10:1-, and C10:2-carnitine as compared with 15 control horses (12 healthy and three with acute myopathy due to other causes). Analysis of plasma revealed similar results for these predominantly short-chain acylcarnitines. Furthermore, measurement of dehydrogenase activities in lateral vastus muscle from one horse with atypical myopathy indeed showed deficiencies of short-chain acyl-CoA dehydrogenase (0.66 as compared with 2.27 and 2.48 in two controls), medium-chain acyl-CoA dehydrogenase (0.36 as compared with 4.31 and 4.82 in two controls) and isovaleryl-CoA dehydrogenase (0.74 as compared with 1.43 and 1.61 nmol min(-1) mg(-1) in two controls). A deficiency of several mitochondrial dehydrogenases that utilize flavin adenine dinucleotide as cofactor including the acyl-CoA dehydrogenases of fatty acid beta-oxidation, and enzymes that degrade the CoA-esters of glutaric acid, isovaleric acid, 2-methylbutyric acid, isobutyric acid, and sarcosine was suspected in 10 out of 10 cases as the possible etiology for a highly fatal and prevalent toxic equine muscle disease similar to the combined metabolic derangements seen in human multiple acyl-CoA dehydrogenase deficiency also known as glutaric acidemia type II.

Pulmonary arteriovenous malformations and migraine: a new vision.

Migraine is a common neurological disorder with a great impact on the quality of life and social activities. Pulmonary arteriovenous malformations (PAVMs) are mostly congenital, with a prevalence of 5-50% in patients with hereditary hemorrhagic telangiectasia (HHT). A high prevalence of PAVMs is found in patients with HHT and migraine. Embolization of PAVMs seems to decrease the prevalence of migraine. Different pathophysiological hypotheses have been proposed to explain the association between migraine and the different right-to-left shunts. This review article describes the association between a pulmonary right-to-left shunt and the occurrence of migraine.

Effect of exercise on apparent total tract digestibility of nutrients and faecal recovery of ADL and TiO2 in ponies.

Exercise and physical training are known to affect gastrointestinal function and digestibility in horses and can lead to inaccurate estimates of nutrient and energy digestibility when markers are used. The effect of exercise on apparent nutrient digestibility and faecal recoveries of ADL and TiO2 was studied in six Welsh pony geldings subjected to either a low- (LI) or high-intensity (HI) exercise regime according to a cross-over design. Ponies performing LI exercise were walked once per day for 45 min in a horse walker (5 km/h) for 47 consecutive days. Ponies submitted to HI exercise were gradually trained for the same 47 days according a standardized protocol. Throughout the experiment, the ponies received a fixed level of feed and the daily rations consisted of 4.7 kg DM of grass hay and 0.95 kg DM of concentrate. The diet was supplemented with minerals, vitamins and TiO2 (3.0 g Ti/day). Total tract digestibility of DM, organic matter (OM), CP, crude fat, NDF, ADF, starch, sugar and energy was determined with the total faeces collection (TFC) method. In addition, DM and OM digestibility was estimated using internal ADL and the externally supplemented Ti as markers. Urine was collected on the final 2 days of each experimental period. Exercise did not affect apparent digestibility of CP, crude fat, starch and sugar. Digestibility of DM (DMD), OM (OMD), ADF and NDF tended to be lower and DE was decreased when ponies received the HI exercise regime. For all treatments combined, mean faecal recoveries of ADL and Ti were 87.8±1.7% and 99.3±1.7%, respectively. Ti was not detected in the urine, indicating that intestinal integrity was maintained with exercise. Dry matter digestibility estimated with the TFC, ADL and Ti for ponies subjected to LI exercise were 66.3%, 60.3% and 64.8%, respectively, while DMD for HI ponies were 64.2%, 60.3% and 65.2%, respectively. In conclusion, physical exercise has an influence on the GE digestibility of the feed in ponies provided with equivalent levels of feed intake. In addition, the two markers used for estimating apparent DMD and OMD indicate that externally supplemented Ti is a suitable marker to determine digestibility of nutrients in horses performing exercise unlike dietary ADL.

Genotype-phenotype relationship in hereditary haemorrhagic telangiectasia.

Hereditary haemorrhagic telangiectasia (HHT) is an autosomal dominant disorder characterised by vascular malformations in multiple organ systems, resulting in mucocutaneous telangiectases and arteriovenous malformations predominantly in the lungs (pulmonary arteriovenous malformation; PAVM), brain (cerebral arteriovenous malformation; CAVM), and liver (hepatic arteriovenous malformation; HAVM). Mutations in the ENG and ALK-1 genes lead to HHT1 and HHT2 respectively. In this study, a genotype-phenotype analysis was performed. A uniform and well classified large group of HHT patients and their family members were screened for HHT manifestations. Groups of patients with a clinically confirmed diagnosis and/or genetically established diagnosis (HHT1 or HHT2) were compared. The frequency of PAVM, CAVM, HAVM, and gastrointestinal telangiectases were determined to establish the genotype-phenotype relationship. The analysis revealed differences between HHT1 and HHT2 and within HHT1 and HHT2 between men and women. PAVMs and CAVMs occur more often in HHT1, whereas HAVMs are more frequent in HHT2. Furthermore, there is a higher prevalence of PAVM in women compared with men in HHT1. In HHT1 and HHT2, there is a higher frequency of HAVM in women. HHT1 has a distinct, more severe phenotype than HHT2. There is a difference in the presence of symptoms between men and women. With these data, genetic counselling can be given more accurately when the family mutation is known.

SMAD4 mutations found in unselected HHT patients.

BACKGROUND: Hereditary haemorrhagic telangiectasia (HHT) is an autosomal dominant disease exhibiting multifocal vascular telangiectases and arteriovenous malformations. The majority of cases are caused by mutations in either the endoglin (ENG) or activin receptor-like kinase 1 (ALK1, ACVRL1) genes; both members of the transforming growth factor (TGF)-beta pathway. Mutations in SMAD4, another TGF-beta pathway member, are seen in patients with the combined syndrome of juvenile polyposis (JP) and HHT (JP-HHT). METHODS: We sought to determine if HHT patients without any apparent history of JP, who were undergoing routine diagnostic testing, would have mutations in SMAD4. We tested 30 unrelated HHT patients, all of whom had been referred for DNA based testing for HHT and were found to be negative for mutations in ENG and ALK1. RESULTS: Three of these people harboured mutations in SMAD4, a rate of 10% (3/30). The SMAD4 mutations were similar to those found in other patients with the JP-HHT syndrome. CONCLUSIONS: The identification of SMAD4 mutations in HHT patients without prior diagnosis of JP has significant and immediate clinical implications, as these people are likely to be at risk of having JP-HHT with the associated increased risk of gastrointestinal cancer. We propose that routine DNA based testing for HHT should include SMAD4 for samples in which mutations in neither ENG nor ALK1 are identified. HHT patients with SMAD4 mutations should be screened for colonic and gastric polyps associated with JP.

Equine metabolic myopathies with emphasis on the diagnostic approach. Comparison with human myopathies. A review.

This review gives an overview of the presently known human and equine metabolic myopathies with emphasis on the diagnostic approach. Metabolic myopathies are muscle disorders caused by a biochemical defect of the skeletal muscle energy system, which results in inefficient muscle performance. Myopathies can arise in different levels of the metabolic system. In this review the metabolic myopathies are categorized in disorders of the carbohydrate metabolism, lipid metabolism, mitochondrial myopathies (other than those described in lipid metabolism), disorders of purine metabolism, primary disorders involving ion channels and electrolyte flux and secondary or acquired metabolic myopathies.

SMAD4 gene mutation increases the risk of aortic dilation in patients with hereditary haemorrhagic telangiectasia.

BACKGROUND: Mutations in the genes ENG, ACVRL1 and SMAD4 that are part of the transforming growth factor-beta signalling pathway cause hereditary haemorrhagic telangiectasia (HHT). Mutations in non-HHT genes within this same pathway have been found to associate with aortic dilation. Therefore, we investigated the presence of aortic dilation in a large cohort of HHT patients as compared to non-HHT controls. METHODS: Chest computed tomography of consecutive HHT patients (ENG, ACVRL1 and SMAD4 mutation carriers) and non-HHT controls were reviewed. Aortic root dilation was defined as a z-score>1.96. Ascending and descending aorta dimensions were corrected for age, gender and body surface area. RESULTS: In total 178 subjects (57.3% female, mean age 43.9±14.9years) were included (32 SMAD4, 47 ENG, 50 ACVRL1 mutation carriers and 49 non-HHT controls). Aortopathy was present in a total of 42 subjects (24% of total). Aortic root dilatation was found in 31% of SMAD4, 2% of ENG, 6% of ACVRL1 mutation carriers, and 4% in non-HHT controls (p<0.001). The aortic root diameter was 36.3±5.2mm in SMAD4 versus 32.7±3.9mm in the non-SMAD4 group (p=0.001). SMAD4 was an independent predictor for increased aortic root (ß-coefficient 3.5, p<0.001) and ascending aorta diameter (ß-coefficient 1.6, p=0.04). CONCLUSIONS: SMAD4 gene mutation in HHT patients is independently associated with a higher risk of aortic root and ascending aortic dilation as compared to other HHT patients and non-HHT controls.